The present invention relates to a printing cylinder/roller cleaning apparatus for a printing press, which cleans the circumferential surface of a printing cylinder, e.g., a blanket cylinder, an impression cylinder, or a transfer cylinder, and the circumferential surface of a roller, e.g., a form roller or a vibrating roller.
Generally, a printing cylinder/roller cleaning apparatus of this type has a cleaning cloth take-up mechanism comprising a pair of rotatably supported roller-shaped cloth guides pressed against the circumferential surface of a printing cylinder/roller through a cleaning cloth, a supply shaft for supplying the cleaning cloth to the cloth guides, and a take-up shaft for taking up the cleaning cloth supplied from the supply shaft. The cleaning cloth is pressed against the circumferential surface of the printing cylinder/roller by intermittently taking up the cleaning cloth on the take-up shaft from the supply shaft, and the residue, e.g., ink dust or paper dust on the circumferential surface of the printing cylinder/roller is wiped with the cleaning cloth, thereby cleaning the circumferential surface of the printing cylinder/roller. In this case, when the cleaning cloth is taken up in the downstream side of the printing cylinder/roller, the cleaning cloth can be undesirably caught in the printing cylinder/roller. Hence, the supply shaft must be provided with a countermeasure so that the cleaning cloth will not be pulled unless the cleaning cloth is taken up.
An example of an apparatus provided with such a countermeasure is a cylinder cleaning apparatus disclosed in Japanese Patent Laid-Open No. 2-20349. In the cylinder cleaning apparatus disclosed in this official gazette, a rotation stop mechanism comprising a ratchet wheel mounted on the shaft end of a supply shaft, a ratchet to be engaged with this ratchet wheel, an air cylinder for engaging and disengaging the ratchet with and from the ratchet wheel, and a spring for biasing the ratchet away from the ratchet wheel is provided to the supply shaft. When the cleaning cloth is to be taken up on the take-up shaft, while the ratchet is separated from the ratchet wheel by the biasing force of the spring, the take-up shaft is driven by a take-up driving unit to take up the cleaning cloth. Unless the cleaning cloth is to be taken up, the ratchet is engaged with the ratchet wheel against the biasing force of the spring by the operation of the air cylinder as the driving unit of the rotation stop mechanism, so that rotation of the supply shaft in the supply direction is prohibited, thereby preventing the cleaning cloth to be pulled out.
However, in the conventional cylinder cleaning apparatus described above, the driving unit for driving the rotation stop mechanism comprising the air cylinder is required in addition to the take-up driving unit for the take-up shaft. In addition, since take-up driving of the take-up shaft and rotation regulation release of the supply shaft must be performed almost simultaneously, when the take-up driving mechanism and the rotation stop mechanism respectively having a separate driving means are to be interlocked, the entire apparatus is increased in size, and the operation becomes complicated, so that a smooth operation cannot be obtained.